Magnetic Resonance Imaging (MRI), also called Spin imaging, Nuclear Magnetic resonance imaging (NMRI) is a widely used medical technique, which is a great progress after Computed Tomography (CT). Since 1980's, MRI has been developing very fast and utilizing in different fields. Its basic principle is that by disposing a body in a special magnetic field, and the body's hydrogen atoms can be polarized; then radio frequency pulses are used for stimulating the hydrogen nuclei of the body, and the hydrogen nuclei absorb RF energy and start resonating. After stopping the RF pulse, hydrogen nuclei emit a specific radio frequency signal, which is detected by RF coils (RF antennas), the specific radio frequency signal is transmitted to a computer and an MR imaging of region of interest (ROI) of the body is reconstructed.
MRI can provide a lot of information of ROI of the body, more than other medical imaging. It is very easy to get anatomy imaging along cross section/sagittal section/coronal section of ROI of the body. Furthermore, the MRI art has other advantages, it does not produce ionizing radiation for the body, and therefore there is no adverse effects on the body, so the MRI art is used widely in medical field.
The RF coil is an important component of the magnetic resonance imaging system, and the RF coil can not only generate RF pulses for exciting hydrogen nuclei of the body, but also receive magnetic resonance signals of the body. The magnetic resonance signals can be processed later to reconstruct anatomy imaging, which may be 2D/3D imaging. In order to acquire better MR signal and improve signal noise ratio (SNR) of the imaging, a local coil (RF coil) is widely used. Commonly, the local coil is specifically designed for corresponding part of the body, such as head coil, wrist coil, spine coil, etc.
The RF coil is connected to a computer of MR system via transmitting lines. In consideration of convenience for operating this tool, there is only one cable with several inner wires connecting to coil elements of the RF coil. However, as a number of transmission channels increases, the outer diameter of the cable also increases, so the cable becomes somewhat rigid. In addition, the cable is fixed to the RF coil, and there is less movement space between joining portion therebetween, and it is not facilitate to use this kind of RF coil.